Mold for rubber heels



Apr. 10, 1923.

| HOLMES MOLD FOR RUBBER HEELS Filed Aug. 23, 1921 2 sheets-sheet'l 46. v V 1a *5 J11 2% J2 'fi flk fivqzfirt Apr. 10-, 1923. 1,451,510 L. HOLMES v MOLD [FOR RUBBER HEELS Fild Aug. 25, 1921 2 sheets-shee t 2 f "F 1, 7" W \V msacnusnrrs.

MQLD FOR RUBBER HEELS.

application filed August 23, 1921. serial ivo..4e4,ee4.

To all whom it may concem:

Be it known that I, Luv: Homes, 9. citizen of the .United States, and resident of Raginham, county of Bristol, Commonwealth of assachusetts, have invented an Improvement in Molds for Rubber Heels, of which the following description, in connection with the accompanying drawings, is aspecifica tion, like characters on the drawings representing like parts in each of the several views. j

This invention relates to molds for. the manufacture of molded heels of shoes and boots and more particularly to a three-part mold of the general type commonly em ployed in making heels of rubber and rubber compositio While not in all respects limited thereto, the mold of the present in vention is particularly adapted and designed for the making of rubber heels of a so-called scoop shape, i. e. a heel that is concavoconvex in crosssection, but relatively flat in longitudinal section at its forward or breast portion. One principal object of the invention is to provide a mold for-making'heels of this type wherein the fin that unavoidably is squeezed out from the heel in 7 thereof, extends out laterally around the heel whereb it may be trimmed oif readily and conveniently by the rotary trimming knives of a suitable machine',which is not possible in cases where the fin projects downward instead of laterally. A further object is to provide a three-part heel mold with a relatively light middle plate portion, whereby this portion is easy to handle, it being understood that this middle plate is the one requiring to be lifted and manipulated to knock out the heels, and is of a considerable dimension with the multiple molds commonly in use, which may be adapted to produce fiftysix or more heels at a single operation. further object is to provide a three-part mold that is easy to open and shut and also easy to keep clean. A still further object is to provide a three-part mold wherein the three parts of the mold are securely interlocked by the provision ofstop the respective plates, these stop shoulders eing also associated with and forming part of the operating elements of the mold. The foregoing and other objects and advantages of the invention will more fully appear from the following detailed description taken in connection with the accompanying drawings,

the molding shoulders on and the distinctive features of novelty will be'pointed out-in the appended claims.

Referring to the drawings:

Fig. 1 is a perspective view showing the three-part mold of my invention with the three mold plates separated and ready for assemblage;

Fig. 2 is a longitudinal vertical-section of the mold on line 2-2 of Figure 3 withthe plates assembled;

Fig. 3 is a transverse section on line 3-3 of Figure 2;

. Fig. 4 is a partial elevation showin the bottom plate of a multiple mold embo ying the invention;

Fig. 5 is a partial elevation showing the middle plate of a multiple mold;

Fig. fiisan elevation of a heel produced by the mold of the invention and prior to the trimming of the fin therefrom; and

Fig. 7 is a transverse section of the heel on line 7-7 of Fig. 6.

Referring first to Figures 1 2 and 3 which show the application of the invention in a single mold, 10 indicates the bottom plate of the mold which is formed with a matrix cavity 11 in its upper face of a shape corresponding to the contour ofthe heel bottom. Since the mold is designed for making scoopshaped heels, this cavity is concave in cross section as indicated at 11*, while in longitudinal section its rear portion curves upward as indicated at 11 to the upper surface of the plate, while its forward portion is relatively flat as indicated at 11. ing around this cavity and spaced a small distance therefrom is a valley 12adapted to receive the overflow of the rubber which is inevitably squeezed out to some extent from the mold cavity as pressure is applied to mold the heel. .13 indicates the middle plate. In accordance with my invention this plate has an opening therethrough corresponding to, the peripheral outline of the heel with vertical walls which extend upward through the plate from the plate bottom as indicated at 14 around said opening except at the front or breast portion of the mold cavity where the corresponding wall 14 is constituted by the convex face of a formed downward projection 140 at this portion of the middle plate. The opposite side of this formed projection constitutes a shoulder abutting squarely against a corresponding vertical shoulder formed on the bottom plate Extendits forward end a square shoulder as indicated at 14:, while the inner portion of the bottom of this projection fits closely against the bottom. of the cavity wall 11 of the bottom plate as indicated at 1%. The top plate 15 has its preipheral portion fitting down closely upon the middle plate as indicated at 15. This plate is equipped with a projection 15 extending into the cavity 11 and constituting the top wall thereof, for this purpose having its face convex in cross section and concave with a flattened front portion in longitudinal section, i, e. corresponding to the curvature of the matrix bottom. This projection 15 presents at g which fits and abuts against a shoulder of the middle plate 13 constituted by an upward continuation of the wall 14?. Thus a rigid and secure backing is obtained of each super-7 posed plate against the next lower plate in a direction forward of the heel and in the direction to withstand the pressures encountered in molding the heel, this backing being obtained by the wall 14; with respect to the middle and bottom plates, and by the wall 15 with respect'to the middle and top plates. The excess rubber is squeezed out between the middle and lower plates into'the valley 12 forming a peripheral fin F which extends out laterally from the body of the heel H in a direction where it may be readily trimmed oil by usual rotary trimming or shearing knives, this being in distinction from previous molds producingthis type of heel where a portion or all or the fin has projected downwardly instead of laterally, and hence required to be cut oil by hand. 16, 17 denote pins in the top and bottom plates respectively which fit into holes 18, 19 of the middle and bottom plates fordeterminingthe alinement of the three plates and holding them properly assembled. Referring to Figures 4 and 5, 20V indicates a base plate or slab for a multiple mold to which a series of rows of individual bottom plates 10' may be riveted or otherwise secured. These individual mold plates 10' substantially to the bottom plates 10 already described and they are arranged end to end in, rows with channels 21 betweenthe rows which constitute overflow valleys into which the excess of he rubber may flow in the molding of the heels. 22 indicates the middle plate of the multiple mold which may conveniently be formed as a single plate member with openings therethrough presenting vertical walls 14 similarly as already described and having the same downward the appended claims rather than to the forecorrespond a middle plate having a reerero projections 1&0 at the breast portions of the matrices, these projections constitutin abutments having bearing against shoul ers or ledges 14 of the bottom plates as already described. The multiple top plate (not shown) may be a single plate member with series of convex downward projections 15 the same as already described. In addition to the advantages already mentioned the present mold is also a valuable and important improvement in that it presents a construction permitting a better and more com= plete escape of gases in the molding operation, for the reason that its construction eliminates air traps or'pockets. I am aware that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and 1 therefore desire the present embodiment to be considered in all respects as illustrative and not restrictive reference being had to going description to indicate the the invention.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A three-part mold constructed and arranged for molding scoop-shaped rubber heels presenting abutting shoulders between each of the mold members at the front or breast portion of the heel cavity.

' 2. A three-part mold constructed and arranged for making scoop-shaped heels consisting in a bottom platehaving a scoopshaped cavity, a middle plate havingan opening therethrough registering with said cavity, with. a downward projection at the breast portion thereof abutting against a shoulder of the bottom plate, and a top plate having a scoop-shaped projection extending into said cavity, constituting the top wall thereof, and having a shoulder abutting against a vertical wall of the middle plate.

3. A multiple three-part mold comprising a base plate or slab with a series of bottoml mold plates secured thereto in',rows with: valleys between said rows, each of said bottom plates having .a matrix cavity therein, series of openings registering with said cavities and having downward projections at the breast portions thereof, and a top plate having a series of convex projections fitting into said cavities to complete the mold matrices.

In testimony whereof, I have name to this specification.

LEVI HOLRES.

scope of signed my 

